Mobi and MagSafe

My tandem mobi started getting unusual cartridge alarms two months ago. After five in a row I called tandem and they replaced the pump, but mentioned something in the call that I’m curious if others have experienced/know to be true.

Essentially, the customer service rep asked me if I’ve ever let my pump near anything magnetic including a MagSafe. I had one on my phone at the time, which I have now switched to be extra careful, but didn’t even know this could be a thing? Is this something well known? I believe phones in general are magnetic now so should we keep the mobi away from our phones at all time? Seems unrealistic and wanted others opinions.